Channel-tubing



A. McINTOSH CHANNEL TUBING. APPLICATION mp0 APR. 17. 1914.

Patented Aug. 17, 1920.

ATTORIVE v19 UNITED STATES PATENT OFFICE.

JAMES A. MoINTOSI-I, OF DETROIT, MICHIGAN, ASSIGNOR, BY MESNE ASSIGNMENTS, TO STANDARD TOOL & MANUFACTURING COMPANY, OF DETROIT, MICHIGAN, A

CORPORATION ,OF MICHIGAN.

CHANNEL-TUBING.

Specification of Letters Patent. Patented Aug, 17, 1920.

Application filed April 17, 1914. Serial No. 832,543.

To all whom it may concern:

Be it'known that I, J AMES A. lVICINTOSH,.

and State of Michigan, have invented certain new and useful Improvements in Channel-Tubings, of which the following is a specification, reference being had therein to the accompanying drawings.

The invention relates to channel tubing such as is used for the formation of panel frames, as for instance, wind-shields. It is the object of the invention to obtain a construction that may be formed up from a flat blank or strip of sheet metal, and in which the seam is so formed and located as to be firmly interlocked and also sealed and protected from exposure.

In the drawings:

Figure 1 is an enlarged cross section showing my improved tubing; and

Fig. 2 is a similar view showing a modilied construction.

A is theouter portion of the tubing and B the channel portion thereof. Such tubing has heretofore been formed either from a seamless tube of greater diameter, which is refashioned into the desired section or from fiat strips which respectively form the cylindrical and the channel. portions and are seamed together at the. point of juncture. The first of these constructions is expensive to manufacture and the latter construction is objectionable, first, because the seam is exposed to view; and second, because it is not protected from the weather. With my improved construction I have avoided both difliculties by forming the tube from a single blank or sheet metal strip, which is fashioned to form both the outer cylindrical portion and the channel portion of the tube. The edges of the strip are formed with interlocking seam-hooks located in the channel portion of the strip and so arranged that they cannot be disengaged. Specifically, C is one of the sides of the channel portion which is formed continuous with the ad jacent cylindrical portion. D is a laterallyextending return-bent hook formed at the lower end of the portion C. E is the opposite side of the channel portion, and F is the bottom thereof, both being formed as continuations of the cylindrical portion; and G is a return-bent hook upon the end of the portion F, which is engaged and interlocked with the hook D.

The construction as above described is one that may be easily formed up from a sheet metal strip by a method forming no part of the present invention, and when the seam formed by the hooks D and G is compressed there is no possibility of accidental disengagement. This is for the reason that the bend of the hook G abuts against the side C and the bend of the hook D is in contact with the outer edge of the hook G. Furthermore, the joint is formed at the corner of the channel. and is completely sealed. Another advantage of the construction is that the thickness of the several plies forming the seam extends within the circular portion of the tube and does not interfere with the flat bottom of the channel, while the location of this at the bottom of the channel instead of at the side thereof renders it easier to fit a filler block in the section of the tube where this is desired.

In Fi 2 is shown a modified construction, in which the tube is formed of two strips, the strip H forming the bottom of the channel and having oppositely return-bent hooks I and l at its ends which engage hooks on the other blank similar to the hook D.

\Vhat'I claim as my invention is 1. A channel windshield tubing, comprising a fashioned sheet metal blank having an integral channel portion and an outer surrounding portion, the opposite edge portions of said blank meeting at the intersection of one side and the bottom of said channel section, and being bent to form a lock seam of lesser width than said channel, the thickness of said seam being located in the space between said channel portion and outer tubing, and the depth of said channel being materially less than the depth of the outer surrounding portion so as to form a comparatively rigid brace between the side walls thereof.

2: A channel windshield tubing, comprising a fashioned sheet metal blank having an integral inner channel and uninterrupted outer surrounding portions, the opposite edge portions of said blank meeting in the bottom portion of the channel and being bent to form a lock seam with the thickness of the seem in the space between said channel portion and the outer surrounding porparatively rigid brace between the side Walls thereof.

In testimony whereof I aflix my signature 1n presence of two Witnesses.

JAMES A. MoINTOSI-I.

Witnesses:

JAMES P. BARRY, HENRIETTA E. BOWMAN. 

